As the guiding principle, this arrangement is of a collaborative nature on issues that are of mutual interest to the US Environmental Protection Agency (EPA) and the National Institute of Environmental Health Sciences (NIEHS). This IAG covers two specific projects that will be done in a collaborative fashion between investigators at the EPA Human Studies Facility (HSF) and NIEHS investigators. Both EPA and NIEHS investigators will be involved in the planning and execution of these studies. The two projects are designed to collect bronchial cells by fiberoptic bronchoscopy with endobronchial brush biopsy and/or BAL. Bronchoscopy is proposed in normal and asthmatic subjects, and in subjects with specific genotypes of interest. All samples generated by bronchoscopy (bronchial and alveolar cells, BAL) will be shared between EPA and NIEHS investigators for in vitro studies. All information will be shared including correlative clinical information about phenotype of individuals from whom samples are obtained. In addition and in order to facilitate cooperation, BAL fluid and cells may be obtained from ongoing EPA studies and shared with NIEHS investigators.